Rotational intravascular imaging or sensing technologies, for example, optical coherence tomography (OCT), intravascular ultrasound (IVUS), near infrared (NIR) spectroscopy, and others typically employ point-scanning beam patterns in the shape of a helix, which captures information in rotational and longitudinal directions. A three-dimensional space scanned within a single rotational period generates information which is usually projected into a planar (2D) format for display on a video monitor or other display device. However, such a planar format includes a discontinuity in the data because of longitudinal displacement of the beam during rotation. For example, a data discontinuity, or seam line, is generated at 0° and at 360°. Such a seam line is a disadvantageous artifact of the planar format.
In addition to the seam line artifact, information acquired with a catheter which is placed within a vessel alongside a guidewire can contain an artifact arising from the inability of the beam energy (e.g. light or sound) to adequately penetrate the guidewire. Thus, OCT, rotational IVUS, Intravascular Spectroscopy (IS), Photo-Acoustic Tomography (PAT), or any intravascular imaging or sensing method which uses a rotating transducer or probe in parallel with at least one guidewire or some other shadowing element creates an artifact in the information acquired in every rotation. Such an artifact, generally known as a guidewire shadow, has traditionally been considered an unavoidable but tolerable discontinuity or gap in the information acquired.
There have been attempts to minimize the effects of the seam line or guidewire shadow artifacts. For example, minimizing the seam line artifact by keeping the pitch of the helix tight (high rotation to translation ratio) and thus reducing the longitudinal displacement incurred between the first and last rotational position in a single frame is known in the art. However, this approach only minimizes the appearance of the seam line and does nothing to address the guidewire artifact. There is currently no method known to minimize the effects of both the seam line and guidewire artifacts in an intravascular imaging modality.